The invention relates to a device for positioning, holding or gripping, comprising a positioning, holding or gripping mechanism actuated by a rotatable motor means such as an electric motor.
The invention is particularly useful for holding, positioning or gripping pieces of automobile body work, of the type comprising a housing containing a movable device movable in translation under the action of an actuating means.
U.S. Pat. No. 5,483,135 discloses a system and process for controlling the operation of vehicle glass, which is not usable for holding, positioning or gripping pieces of automobile bodies.
EP 0 243 599 discloses a device for holding, positioning or gripping, particularly for holding, positioning or gripping pieces of automobile body work, of the type comprising at least one housing containing a movable device movable in translation under the action of an actuating means comprising an electric motor.
The two first embodiments disclosed in EP 0 243 599 relate to mechanisms movable under the action of a rotatable electric motor, whilst the third embodiment described in EP 0 243 599 relates to a mechanism movable under the action of a linear electric motor.
The devices of EP 0 243 599 are hardly used in practice because of the risk of heating and electrical damage, in particular in a gripping position.
The invention has for its object to overcome the drawbacks of the prior art, by providing a new device comprising an electric motor of a particular type as well as control means of a particular type, whilst ensuring a precision and force of holding, positioning or gripping, comparable to the characteristics of the prior art.
The invention has for its object a device for holding, positioning or gripping particularly to hold, position or grip pieces of automobile body work, of the type comprising at least one housing containing a movable device movable in translation under the action of an actuating means comprising an electric motor, characterized in that the electric motor is a DC motor or a reversible motor equivalent adapted to carry out electrical braking, so as to immobilize the electric motor in a preliminary approach position to a full force position, the device comprises means for controlling and supplying the electrical motor, and in which the control means comprise means for position detection, so as to control the supply means for the electric motor as a function of the position detected by said means, to avoid supply of the electrical motor in a blocked position having the risk of overheating and damage to the electric motor.
According to other characteristics of the invention:
the control means comprise starting control means giving a start order to supply the electric motor, detection means of a position when arriving in abutment and means for memorizing this position of arriving at abutment as an initial reference position of the device, arranged in combination to start the device in a mechanically blocked or abutment position,
the device comprises a modular assembly for supplying energy and for controlling the electric motor, connected to a rotation detector such as a rotatable coder,
said modular assembly comprises a means for switching between several predetermined positions each corresponding to a path, an angle or a movement of a selected value to carry out a predetermined positioning, holding or gripping,
the modular assembly for energy supply and controlling the electric motor comprises a memory adapted to memorize the position of the motorized mechanism during an actual cycle of operation,
the modular assembly for supplying with energy and for control is adapted to compare an actual position of the motorized mechanism with a preceding position of the motorized mechanism, so as to detect an anomaly of operation of the device,
the actuating means comprises a casing containing a pinion mounted and directly driven by the electric motor shaft, as well as a toothed wheel forming the nut for driving in translation a screw-threaded rod of the movable assembly,
the actuating means is arranged to ensure a non-reversibility function or for holding in position the device upon stopping in the absence of electrical supply of the electrical means,
said casing comprises a pierced closure plate or cover carrying on one side the electrical motor whose shaft extends through the hole in the closure plate or cover, so as to support said pinion from the side opposite that carrying the electric motor.